I've got a bit of a pet peeve in this game, the fact that you have to take both Aragon and Raiko into every battle. Personally, I like to rotate my roster frequently so that everyone gets a fair turn, and to help keep everyone's levels roughly equal. Two fixed slots makes this a tad difficult, and it seems fairly unnecessary too. I'm used to Strategy RPGs making the player take the main character into virtually every fight, and I can work with that, but having Raiko along all the time on top of that's a pain.
I really just wish I could kick the two of them out of the part from time to time, or only had to take one of the two into each battle.